Crystals are indeed faction restricted when they're only found on set items belonging to one side or the other.

No their not because i have players in my republic guild who have purple light sabers, Also a guy who killed the world boss on Alderaan over 300 times has looted the white crystal 4 times since live, If you go look on the official forums you will see guides on how to acquire the purple and white crystals for both factions.

The white lightsaber crystal is in game. I have seen a Jedi Sage lvl 50 named Julanna or something similar to that that had it.
I was at the Alderaan World boss when they turned up. They asked if I was wanting the white crystal. I said yes, and they brought out their lightsaber with a white blade. She (female toon) asked if I knew the drop rate. I replied, I did not. Then both of us attacked the boss to see if it would drop. She disappeared half way through the fight but I was able to solo boss and the crystal did not drop. They did not mention if the world boss dropped the crystal.

I don't know if white can be found in any other ligjtsabers like purple can, but I can confirm I have seen a white lightsaber blade. This is not a troll. This happened last Sunday 15th January.

Im posting this cause I really want this crystal. It would be a shame if it was republic only.

I play on European The Red Eclipse server. My toon is Al-yamin level 50 sith sorcerer. Feel free to contact me in game if you have further questions. - AlphaCephei Link

I was in a Huttball game tonight with someone who had a white lightsaber blade, but I wasn't aware they were so rare and I didn't think to ask him about it.

I managed to find a red crystal with no light/dark requirement for my light side assassin, but I can't remember where. I think it was a quest reward that I transplanted. I just hope the new blade colors in 1.2 will be cool. Though I think it would be nice to remove the limitations of light/dark on all servers except the RP ones where it would actually make sense.

I was in a Huttball game tonight with someone who had a white lightsaber blade, but I wasn't aware they were so rare and I didn't think to ask him about it.

I managed to find a red crystal with no light/dark requirement for my light side assassin, but I can't remember where. I think it was a quest reward that I transplanted. I just hope the new blade colors in 1.2 will be cool. Though I think it would be nice to remove the limitations of light/dark on all servers except the RP ones where it would actually make sense.

As of 1.5 none of the crystals are restricted by Light / Dark, meaning that you can now use a green crystal as dark for example. In addition to that, there is a new vendor on your faction's fleet, on the galactic trade market sector, labeled as geologist, that sells various high-end crystals with different colors (purple, cyan, magenta), including white.

If you are not lvl 50 yet, you might find the crystals rather expensive. Most of them are 250,000 credits each, and the white one is even more expensive. Can't remember the exact price, but I remember it being at least a million.